A water soluble analog of Wilkinson catalyst-chloro-tris-(sodium diphenylphosphino-benzene-m-sulfonate) rhodium(I), CAS 67178-14-7, i.e. RhCl(DPM)(3)-has been found to hydrogenate NBR latex. More than 60 mol% hydrogenation can be achieved at 75 degrees C and 1 atmosphere hydrogen pressure. Hydrogenation was accompanied by an increase in gel content of the latex.